The electronic industry has seen growth in the use of flat plastic cards incorporating computer chips therein. These chip or IC cards are also commonly referred as to as "smart cards". A smart card is a card incorporating at least one electronic component to which electrical connection must be made. These cards include contact pads so as to allow electrical connection to the electronic component on the card. Smart cards are commonly used in various consumer oriented machines such as telephones, bank machines, vending machines and the like.
One particular type of smart card commonly used in telephones, especially personal portable telephones, is a mini-card or a mini-SIM (subscriber identity module) card. These cards have a particular industry-accepted standard for size, shape and location of the electronic components and contact pads. These mini-SIM cards are typically installed in the apparatus, such as a cellular phone, by a trained installer.
In order to effect electrical connection between the mini-SIM card and a printed circuit board within the phone, an electrical connector is employed. These connectors also are manufactured in an industry-accepted configuration so that the mini-SIM card may be accommodated by the connector. However, for various purposes, such as for example, to change the subscriber identity, it may be necessary to replace the mini-SIM card within the phone. Thus, the electrical connector used to support the mini-SIM card in the phone must permit the easy replacement of cards therein.
The art has seen numerous electrical connectors specifically designed for use in removably connecting various types of smart cards. In addition, a reader for chip cards with fixed contacts is known, but where the contacts wipe the card along the entire insertion length and thus it is used only in special cases. Typical connector configurations utilize a combination of a base and cover as shown in FIGS. 1 and 1A. FIG. 1 shows a card connector 10 as disclosed in commonly assigned patent application having Ser. No. 08/938,305, filed Sep. 26, 1997 and incorporated by reference herein. Connector 10 is shown prior to assembly with a printed circuit board (PCB) 11. PCB 11 includes a substantially planar base 13 which supports a parallel reading unit 15 thereon. Reading unit 15 has a plurality of metallic contacts 17 protruding therefrom with which a contact pad on a chip card establishes an electrical connection to the PCB. Each contact 17 includes a spring element for deflectable electrical engagement with the contact pad of the IC card and contact tail for termination to PCB 11. Each contact 17 extends from peripheral edges 19 of reading unit 15 to an interior reading area 21 defined in an intermediate area of reading unit 15.
As seen in FIG. 1 and further shown in FIG. 1A, connector 10 includes a planar connector base 12 having a planar connector cover 14 hingedly affixed thereto. Connector base 12 is generally parallel to base 13 of PCB 11 so as to ensure a proper fit thereon. Base 12 includes an intermediate region 16 which allows contacts 17 to protrude through reading area 21 of base 13 and into a plane defined by connector base 12.
Connector cover 14 swings in rotatable relation to base 12. Cover 14 has a smooth upper surface 14a and a lower surface 14b from which at least one latching portion 14c extends. An IC card is insertably supported by cover 14 for movement therewith. Upon insertion of the card in cover 14, cover 14 is rotated toward the upper surface of base 12 and closed therewith. The card is inserted into cover 14 with its contact side facing the base 12 so that electrical contact is effected upon closure of the cover. Each latching portion 14c defines a groove therein which accommodates the IC card in the cover. The latching portions are used to lock the cover and the base so that the pad of the IC card remains in electrical engagement with contacts 17.
Although the aforedescribed connector effectively establishes electrical contact between an IC card and a PCB, its use may not be desirable in configurations where conservation of materials and space is essential. The above design requires at least two housing components which must subscribe to the particular dimensions of a chip card inserted therein. Two additional components are required for construction of the reading guide. In addition, a soldering process is required to fix the connector to the PCB. The required number of components and the extra soldering step required to complete assembly of the chip card reader to a PCB contribute to increased costs associated with manufacture of such reading devices. In addition, the number of parts in the assembly contributes to increased device thickness and increased outside dimensions. Such increased dimensions contribute to problems of packaging the device within an already crowded PCB configuration.
Furthermore, during installation it is quite common for the installer to select a particular SIM card for installation into a particular connector. As a result of transporting, handling and installing such a card, there is a tendency for the contact pads on the card to accumulate dust and debris. Such accumulation may adversely affect the interconnection between the contact pads on the card and the contacts in the connector. Simple rotational movement of the card into engagement with contacts of the base does little to assure clean connection therebetween. Furthermore, as the cover is locked to the base in a separate operation, mechanical connection of the card to the connector is not always assured even where electrical connection is established. Over time the chip card could dislodge from the connector without prior warning.
Thus, it is desirable to provide a chip card reading device which obviates the need for a combination of a cover and base and which implements fewer contacts so as to effect a satisfactory electrical connection using a minimum number of components.